Recently, as interest in traditional fermented foods has increased, methods for preparing various extracts using fermentation techniques have been developed. Accordingly, functional foods, functional cosmetic products and the like produced using fermented medical herb extracts having better performance than that of unprocessed medicinal herbs have been developed.
In the prior art, methods of fermenting medicinal herbs by microorganisms were adopted. For example, Korean Patent Registration No. 10-0319377 discloses a method of fermenting vegetables and medicinal herb juice using Lactobacillus plantarum ATCC 11542. Also, Korean Patent Registration No. 10-0465261 discloses a method comprising preparing a medicinal herb extract from a medicinal herb mixture that contains Astragalus and Lycium Chinense fruit, adding a Lactobacillus bulgaricus culture to the extract, and then culturing the extract.
With the recent trend toward healthy lifestyles, the demand for methods of fermenting medicinal herbs using natural fermentation methods without using artificial factors has increased, and the demand for products produced using the fermented medicinal herbs continues to increase. However, these natural fermentation methods are difficult to use in actual products, due to the risk of spoilage and contamination caused by E. coli, anaerobic bacteria and the like that are harmful to the human body. In an attempt to solve such problems, a method of carrying out sterilization prior to fermentation, such as a boiling method, was developed. In this case, however, active ingredients can be degraded by heat. Thus, there is a need to develop a fermentation method that uses a non-sterilization method.